Genetic variations in vascular endothelial growth factor but not in angiotensin I-converting enzyme genes are associated with endometriosis in Estonian women

Study of single nucleotide polymorphism of vascular endothelium factor in patients with differentiated thyroid cancer

BACKGROUND

Genetic alterations and high levels of the vascular endothelial growth factor (VEGF) are presumptive risk factors for differentiated thyroid cancer (DTC).

OBJECTIVE

This work aims to study the presence of - 634G/C polymorphism of vascular endothelial growth factor (rs2010963) and its' serum level in patients with DTC and comparing these results with those of the control subjects.

MATERIAL AND METHOD

The study was a retrograde case-control study that included seventy patients with DTCin addition to seventy apparently healthy control subjects. Blood sample was taken and subjected to study of - 634G/C VEGF polymorphism (rs2010963) by real time PCR and measurement of its' plasma level by immunoassay kit (ELISA).

RESULTS

Regarding genotyping of VEGFA - 634G/C (rs2010963) polymorphism, there was significant increase in CG and GG genotypes (28.6%, 18.6% respectively) among patients compared to control subjects (20.0%, 4.3% respectively) and significant increase in CC genotype in control subjects (75.7%) compared to patients (52.9%), P = 0.001. The VEGF mean ± SD level was significantly elevated in patients compared to control subjects (1215.81 ± 225.78 versus 307.16 ± 91.81, P = 0.006). Moreover, there was significant increase in VEGF levels in patients with CG and GG genotypes (1295.9 ± 68.74, 1533.08 ± 109.95, respectively) compared to patients with CC genotype (1061 163.25), P = 0.001).

CONCLUSION

There was significant increase in GG and CG genotypes in patients with DTC compared to control subjects which may suggest a predisposing role for these genotypes in development of DTC. Moreover, there was significant increase in serum level of vascular endothelial growth factor in patients with GG and CG genotypes which may reflect the mechanism of these genotypes in development of DTC.

Physiological and pathological roles of Ang II and Ang- (1-7) in the female reproductive system

The local Renin-Angiotensin System (RAS) has been demonstrated to exist in a wide range of tissues and organs, In the female reproductive system, it is mainly found in the ovary, uterus and placenta. The RAS system is made up of a series of active substances and enzymes, in addition to the circulating endocrine renin-angiotensin system. The active peptides Angiotensin II (Ang II) and Angiotensin (1-7) (Ang-(1-7)), in particular, appear to have distinct activities in the local RAS system, which also controls blood pressure and electrolytes. Therefore, in addition to these features, angiotensin and its receptors in the reproductive system seemingly get involved in reproductive processes, such as follicle growth and development, as well as physiological functions of the placenta and uterus. In addition, changes in local RAS components may induce reproductive diseases as well as pathological states such as cancer. In most tissues, Ang II and Ang- (1-7) seem to maintain antagonistic effects, but this conclusion is not always true in the reproductive system, where they play similar functions in some physiological and pathological roles. This review investigated how Ang II, Ang- (1-7) and their receptors were expressed, localized, and active in the female reproductive system. This review also summarized their effects on follicle development, uterine and placental physiological functions. The changes of local RAS components in a series of reproductive system diseases including infertility related diseases and cancer and their influence on the occurrence and development of diseases were elucidated. This article reviews the physiological and pathological roles of Ang II and Ang- (1-7) in female reproductive system,a very intricate system of tissue factors that operate as agonists and antagonists was found. Besides, the development of novel therapeutic strategies targeting components of this system may be a research direction in future.

Polymorphisms and endometriosis: a systematic review and meta-analyses

BACKGROUND

Endometriosis is an estrogen-dependent gynecological disorder that affects at least 10% of women of reproductive age. It may lead to infertility and non-specific symptoms such as chronic pelvic pain. Endometriosis screening and diagnosis are difficult and time-consuming. Late diagnosis (with a delay ranging from 3.3 to 10.7 years) is a major problem and may contribute to disease progression and a worse response to treatment once initiated. Efficient screening tests might reduce this diagnostic delay. As endometriosis is presumed to be a complex disease with several genetic and non-genetic pathogenic factors, many researchers have sought to identify polymorphisms that predispose to this condition.

OBJECTIVE AND RATIONALE

We performed a systematic review and meta-analysis of the most regularly reported polymorphisms in order to identify those that might predispose to endometriosis and might thus be of value in screening.

SEARCH METHODS

The MEDLINE database was searched for English-language publications on DNA polymorphisms in endometriosis, with no date restriction. The PubTator text mining tool was used to extract gene names from the selected publications' abstracts. We only selected polymorphisms reported by at least three studies, having applied strict inclusion and exclusion criteria to their control populations. No stratification based on ethnicity was performed. All steps were carried out according to PRISMA guidelines.

OUTCOMES

The initial selection of 395 publications cited 242 different genes. Sixty-two genes (corresponding to 265 different polymorphisms) were cited at least in three publications. After the application of our other selection criteria (an original case-control study of endometriosis, a reported association between endometriosis and at least one polymorphism, data on women of reproductive age and a diagnosis of endometriosis in the cases established by surgery and/or MRI and confirmed by histology), 28 polymorphisms were eligible for meta-analysis. Only five of the 28 polymorphisms were found to be significantly associated with endometriosis: interferon gamma (IFNG) (CA) repeat, glutathione S-transferase mu 1 (GSTM1) null genotype, glutathione S-transferase pi 1 (GSTP1) rs1695 and wingless-type MMTV integration site family member 4 (WNT4) rs16826658 and rs2235529. Six others showed a significant trend towards an association: progesterone receptor (PGR) PROGINS, interCellular adhesion molecule 1 (ICAM1) rs1799969, aryl-hydrocarbon receptor repressor (AHRR) rs2292596, cytochrome family 17 subfamily A polypeptide 1 (CYP17A1) rs743572, CYP2C19 rs4244285 and peroxisome proliferator-activated receptor gamma (PPARG) rs1801282), and 12 showed a significant trend towards the lack of an association: tumor necrosis factor (TNF) rs1799964, interleukin 6 (IL6) rs1800796, transforming growth factor beta 1 (TGFB1) rs1800469, estrogen receptor 1 (ESR1) rs2234693, PGR rs10895068, FSH receptor (FSHR) rs6166, ICAM1 rs5498, CYP1A1 rs4646903, CYP19A1 rs10046, tumor protein 53 (TP53) rs1042522, X-ray repair complementing defective repair in Chinese hamster cells 1 (XRCC1) rs25487 and serpin peptidase inhibitor clade E member 1 (SERPINE1) rs1799889; however, for the 18 polymorphisms identified in the latter two groups, further studies of the potential association with the endometriosis risk are needed. The remaining five of the 28 polymorphisms were not associated with endometriosis: glutathione S-transferase theta 1 (GSTT1) null genotype, vascular endothelial growth factor alpha (VEGFA) rs699947, rs833061, rs2010963 and rs3025039.

WIDER IMPLICATIONS

By carefully taking account of how the control populations were defined, we identified polymorphisms that might be candidates for use in endometriosis screening and polymorphisms not associated with endometriosis. This might constitute the first step towards identifying polymorphism combinations that predispose to endometriosis (IFNG (CA) repeat, GSTM1 null genotype, GSTP1 rs1695, WNT4 rs16826658 and WNT4 rs2235529) in a large cohort of patients with well-defined inclusion criteria. In turn, these results might improve the diagnosis of endometriosis in primary care. Lastly, our present findings may enable a better understanding of endometriosis and improve the management of patients with this disease.

The impact of vascular endothelial growth factor single nucleotide polymorphisms in the development and severity of endometriosis: A systematic review of the literature

OBJECTIVE

To review the impact of single nucleotide polymorphisms (SNPs) of the vascular endothelial growth factor (VEGF) gene in the development and severity of endometriosis.

SEARCH STRATEGY

We searched Medline, Scopus, Clinicaltrials.gov, EMBASE, Cochrane Central Register of Controlled Trials CENTRAL and Google Scholar databases for published studies in the field.

SELECTION CRITERIA

We included prospective and retrospective observational studies.

DATA COLLECTION AND ANALYSIS

Data extraction was performed using a modified data form that was based in Cochrane`s data collection form for intervention reviews.

MAIN RESULTS

Twenty studies were included that investigated the frequency of the various alleles of the -460C/T, +405G/C, +936C/T, -2578A/C and -1154G/A SNPs. The Hardy-Weinberg equilibrium revealed that the different genotypes were comparable among patients with endometriosis and control women, as well as among patients with mild and severe forms of the disease. No differences were observed in the expression of the various alleles in the majority of cases. Ethnical variations were observed; however, the results should be regarded as inconclusive due to the small amount of available data.

CONCLUSIONS

The results of our meta-analysis suggest that the investigated single nucleotide polymorphisms are unlikely to significantly contribute to the development and severity of endometriosis.

Defining the genetic profile of endometriosis

Endometriosis is a pathological condition which has been extensively studied, since its pathophysiology stems from a broad spectrum of environmental influences and genetic factors. Familial studies aim at defining inheritance trends, while linkage analysis studies focus on the identification of genetic sites related to endometriosis susceptibility. Genetic association studies take into account candidate genes and single nucleotide polymorphisms, and hence target at unraveling the association between disease severity and genetic variation. The common goal of various types of studies is, through genetic mapping methods, the timely identification of therapeutic strategies for disease symptoms, including pelvic pain and infertility, as well as efficient counselling. While genome-wide association studies (GWAS) play a primary role in depicting genetic contributions to disease development, they entail a certain bias as regards the case-control nature of their design and the reproducibility of the results. Nevertheless, genetic-oriented studies and the implementation of the results through clinical tests, hold a considerable advantage in proper disease management. In this review article, we present information about gene-gene and gene-environment interactions involved in endometriosis and discuss the effectiveness of GWAS in identitying novel potential therapeutic targets in an attempt to develop novel therapeutic strategies for a better management and treatment of patients with endometriosis.

Autophagy in endometriosis: Friend or foe?

Endometriosis is a chronic, estrogen-dependent disease and characterized by the implantation of endometrial glands and stroma deep and haphazardly into the outside the uterine cavity. It affects an estimated 10% of the female population of reproductive age and results in obvious reduction in health-related quality of life. Unfortunately, there is no a consistent theory for the etiology of endometriosis. Furthermore, the endometriosis is hard to diagnose in early stage and the treatment methods are limited. Importantly, emerging evidence has investigated that there is a close relationship between endometriosis and autophagy. However, autophagy is a friend or foe in endometriosis is puzzling, the precise mechanism underlying autophagy in endometriosis has not been fully elucidated yet. Here, we provide an integrated view on the acquired findings of the connections between endometriosis and autophagy. We also discuss which may contribute to the abnormal level of autophagy in endometriosis.

Polymorphisms in VEGF and KDR genes in the development of endometriosis: a systematic review

Abstract Objectives: to review studies that used case-control design to verify the association of polymorphisms in VEGF and KDR genes in the development of endometriosis. Methods: the systematic review selected articles published until September 1, 2015 from PubMed, MEDLINE, BVS, SciELO databases, considering the following key words: endometriosis and ("polymorphism" or "SNP" or "genetic polymorphism") and ("VEGF" OR "Vascular endothelial growth factor" or "VEGFR-2" or "Vascular endothelial growth factor-2" or "KDR" or "Kinase Insert Domain Receptor"). Results: 106 articles were identified, only 11 were eligible. Discrepant results were observed regarding polymorphisms in VEGF gene in the development of endometriosis, which can be explained by methodological differences, sample size, eligible control type, using the unadjusted risk estimates and the heterogeneity of the studied population. Only one study investigated polymorphisms in KDR gene in the development of endometriosis, however it was ineligible for this review. Conclusions: to avoid discrepancy in the results, we suggest that the ideal control group should be formed by fertile women and free of gynecological diseases. Multicentric studies with adequate design, involving different population besides the combined analysis on polymorphisms in VEGF and KDR genes are still necessary to contribute in the understanding of this disease, which are social, clinical and economical problems.

Vascular endothelial growth factor pathway in endometriosis: genetic variants and plasma biomarkers

OBJECTIVE

To study single nucleotide polymorphisms (SNPs) involved in angiogenesis (VEGF, PLGF, VEGFR1, VEGFR2, HIF-1α) and plasma levels of the corresponding proteins (VEGF, PLGF, sVEGFR1, sVEGFR2) in women with and without endometriosis.

DESIGN

Allele frequencies of vascular endothelial growth factor (VEGF) pathway SNPs and plasma levels of the corresponding proteins were investigated in patients with endometriosis and in controls.

SETTING

University hospital.

PATIENT(S)

Samples of DNA from 1,931 Caucasian patients were included (1,109 patients with endometriosis and 822 controls). An additional study group included 973 DNA samples from volunteers, self-reported to be healthy without laparoscopic evaluation.

INTERVENTION(S)

Women who underwent a laparoscopy for subfertility and/or pain and healthy volunteers without laparoscopic evaluation.

MAIN OUTCOME MEASURE(S)

Functional SNPs of the VEGF, VEGFR1, VEGFR2, HIF-1α genes and Hap Map tagging SNPs of the PLGF gene were genotyped by using iPLEX technology on a Sequenom MassArray and TaqMan SNP Genotyping Assay. The VEGF levels were determined in ethylenediaminetetraacetic acid plasma samples by using Bio-Plex Protein Array System. PLGF, sVEGFR1, and sVEGFR2 levels were measured in ethylenediaminetetraacetic acid plasma samples by using ELISA Quantikine kits.

RESULT(S)

A significant association was found between the rs2268613 polymorphism in the PLGF gene and PLGF plasma levels. In all study subjects, women with the AA variant of the rs2268613 PLGF gene had significantly lower PLGF plasma levels (median [interquartile range] 9.36 [8.19-10.43] pg/mL) than those with the AG variant (12.1 [11.81-20.84] pg/mL; P(a)=.0085, P(b)=.04), both before and after multiple testing. Plasma levels of VEGF were elevated in endometriosis patients (especially in minimal-mild endometriosis during the menstrual cycle phase) compared with laparoscopic controls but had a moderate diagnostic performance (area under the curve, 0.73) in this discovery dataset. At a cut-off plasma level of VEGF >3.88 pg/mL, minimal-mild stages of endometriosis were diagnosed with a sensitivity of 74% and a specificity of 80% during the menstrual phase of cycle. The associations between the presence of endometriosis and SNPs in PLGF (rs2268614), HIF-1α (rs11549465), and VEGFR1 (rs9582036) genes lost statistical significance after multiple testing.

CONCLUSION(S)

Genetic variants in the PLGF rs2268613 gene may influence plasma levels of the corresponding protein. Plasma levels of VEGF were elevated in endometriosis patients compared with controls. The associations between the presence of endometriosis and SNPs in PLGF (rs2268614), HIF-1α (rs11549465), and VEGFR1 (rs9582036) genes lost statistical significance after multiple testing.

Vascular endothelial growth factor (-460 C/T, +405 G/C, and +936 C/T) polymorphisms and endometriosis risk in Tunisian population

The vascular endothelial growth factor (VEGF), a major angiogenic factor, is known to play an important role in the development of endometriosis. The aim of this study was to investigate the association of three VEGF (-460 C/T, +405 G/C, and +936 C/T) polymorphisms with the risk of endometriosis in the Tunisian population. This study includes 105 women with endometriosis and 150 women with no laparoscopic evidence of disease. Genotyping of the VEGF -460 C/T, +405 G/C, and +936 C/T polymorphisms were performed by polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP). The distribution of genotypes (P = 0.006) and allele (P = 0.0009) frequencies of the +936 C/T polymorphism was significantly different between patients and controls. Patients with stages III-IV endometriosis showed a higher VEGF + 936T allele frequency than controls (P = 0.0001). However, the distribution of genotypes and allele frequencies of the VEGF -460 C/T and +405 G/C polymorphisms did not differ significantly between endometriosis patients and controls. These findings suggest that the VEGF +936 C/T polymorphism may be a risk factor for endometriosis development and the VEGF +936 T allele is associated with an increased risk of stages III-IV endometriosis in the Tunisian population.

The association between vascular endothelial growth factor (VEGF) +405G>C genetic polymorphism and endometriosis

The vascular endothelial growth factor (VEGF) is one of the most important candidate genes for the development of endometriosis, and VEGF genetic polymorphisms might be potentially associated with endometriosis risk. However, the results still remain controversial. The objective of this study aimed to perform a comprehensive meta-analysis to explore a better understanding of the effects of VEGF +405G>C genetic polymorphism on the risk of endometriosis. A total of eleven eligible studies were eventually identified in this meta-analysis, including 2829 endometriosis cases and 2947 controls. In the overall analysis, no significant association between the VEGF +405G>C genetic polymorphism and the risk of endometriosis was detected in all genetic models (for homozygote comparison [CC versus vs. GG]: OR = 1.21, 95% CI 0.67-2.19, P = 0.537; for heterozygote comparison [CG vs. GG]: OR = 1.16, 95% CI 0.86-1.56, P = 0.348; for dominant comparison CC/CG vs. GG: OR = 1.10, 95% CI 0.93-1.30, P = 0.263; for recessive comparison [CC vs. CG/GG]: OR = 1.03, 95% CI 0.73-1.47, P = 0.857; allele comparison [C vs. G]: OR = 0.99, 95% CI 0.70-1.40, P = 0.962). In the subgroup analysis by ethnicities, there was no significant association between VEGF +405G>C genetic polymorphism and endometriosis risk in Asians and/or Caucasians under all genetic models (all P-values >0.05). No publication bias was observed in this study. This meta-analysis supports that the VEGF +405G>C genetic polymorphism is not significant associated with the risk of endometriosis.

Involvement of vascular endothelial growth factor -460 C/T, +405 G/C and +936 C/T polymorphisms in the development of endometriosis

There are inconsistent data on the contribution of vascular endothelial growth factor (VEGF) -460 C/T (rs833061), +405 G/C (rs2010963) and +936 C/T (rs3025039) single-nucleotide polymorphisms (SNPs) to endometriosis in different ethnicities. Therefore, using high-resolution melting curve analysis, the present study examined the distribution of these SNPs in females with endometriosis-related infertility and a control group. None of the three VEGF SNPs were associated with endometriosis-related infertility in the dominant and recessive models. The lowest P-values of the trend were observed for the VEGF +936 C/T (rs3025039) SNP in endometriosis-related infertility (P_trend =0.149). Similarly, haplotype analyses of VEGF SNPs did not demonstrate any SNP combination as a risk for endometriosis-related infertility, and the lowest overall P-values, P=0.141 and P_corr =0.395, were observed for a haplotype (TGT) of the above SNPs. Taken together, these results did not demonstrate the contribution of VEGF C/T, +405 G/C and +936 C/T SNPs to endometriosis-related infertility.

Role of vascular endothelial growth factor polymorphisms (-2578C>A, -460 T>C, -1154G>A, +405G>C and +936C>T) in endometriosis: a case-control study with Brazilians

Background

Endometriosis is regarded as a complex and heterogeneous disease in which genetic and environmental factors contribute to the phenotype. The Vascular Endothelial Growth Factor (VEGF) plays important roles in the pathogenesis of endometriosis. The present study was aimed at investigating the contribution of VEGF polymorphisms as risk factors for the development of endometriosis. This is the first study to evaluate the combined influence of the five most common VEGF polymorphisms.

Methods

This study was conducted at two hospitals from the Brazilian public health system, and comprised 294 women submitted to laparoscopic or laparotomy surgery: 182 patients had a histologically confirmed diagnosis of endometriosis (cases), whereas 112 had no evidence of the disease (controls). The VEGF polymorphisms were determined by TaqMan real-time polymerase chain reaction. The odds ratio (OR) with their 95% confidence intervals (CI) were calculated using an unconditional logistic regression model.

Results

Endometriosis patients and controls did not differ regarding age distribution, whereas the body mass index was significantly lower in endometriosis patients, when compared with controls (23.1 ± 3.9 versus 27.3 ± 5.9, P < 0.001). The evaluation of gynecological symptoms, including dysmenorrhea, non-cyclic chronic pelvic pain, dyspareunia and infertility, indicates significantly higher prevalences among endometriosis cases. The variant allele -1154A was significantly associated with endometriosis, either considering all cases (OR: 1.90, 95% CI: 1.23–2.97), deep infiltrating endometriosis (DIE) (OR: 1.83, 95% CI: 1.16-2.90) or moderate and severe endometriosis (stages III-IV) (OR: 1.97, 95% CI: 1.21-3.19). No significant differences were found in allele or genotype distributions of the –2578C > A, -460 T > C, +405G > C and +936C > T polymorphisms between endometriosis cases and controls. A total of six haplotypes were inferred derived from four polymorphisms (-2578C > A, -460 T > C, -1154G > A and +405G > C). There was a protective association between CCGG haplotype and endometriosis, either considering all cases (OR: 0.36, 95% CI: 0.15–0.86), DIE (OR: 0.37 95% CI: 0.15 – 0.90) or stages III-IV (OR: 0.35 95% CI: 0.13 – 0.95).

Conclusions

The present results indicate a positive association between VEGF -1154G > A and the risk of developing endometriosis, whereas the CCGG haplotype may be protective against the development of disease.

Vascular endothelial growth factor gene polymorphisms contribute to the risk of endometriosis: an updated systematic review and meta-analysis of 14 case-control studies

Endometriosis is a chronic gynecological disease defined as the presence of the endometrium outside the uterine cavity. Endometriosis is a multifactorial and polygenic disease in which angiogenesis may be implicated. Angiogenesis is under the control of numerous inducers, including vascular endothelial growth factor (VEGF). Many studies have reported that VEGF plays a role in the progression of the disease, but individually published studies showed inconclusive results. We investigated the association between VEGF polymorphisms and the susceptibility to endometriosis. The MEDLINE, EMBASE, Web of Science, and CBM databases were searched for all articles published up to June 25, 2012, which addressed VEGF polymorphisms and endometriosis risk. We investigated the potential association between VEGF polymorphisms and the risk of endometriosis. Fourteen studies were included with a total of 3313 endometriosis cases and 3393 healthy controls. Meta-analysis results showed that the rs699947 (A>C) and rs1570360 (G>A) polymorphisms in the VEGF gene were associated with a decreased risk of endometriosis, while rs3025039 (C>T) might increase the risk of endometriosis. However, the rs833061 (T>C) and rs2010963 (G>C) polymorphisms of the VEGF gene did not appear to have an influence on endometriosis susceptibility. Results from the meta-analysis suggest that the rs3025039 (C>T) polymorphism of the VEGF gene increases the risk of endometriosis, but the rs699947 (A>C) and rs1570360 (G>A) polymorphisms might be protective factors for endometriosis.

Association of the vascular endothelial growth factor gene polymorphisms (-460C/T, +405G/C and +936T/C) with endometriosis: a meta-analysis

Published data on the association between the vascular endothelial growth factor (VEGF) gene -460C/T (rs833061), +405G/C (rs2010963), +936T/C (rs3025039) polymorphisms and endometriosis risk are inconclusive. Eleven eligible case-control studies including 2690 cases and 2803 controls were included in this meta-analysis through searching the databases of PubMed and CBMdisc (up to August 1, 2011). In the overall analysis, no significant association between the -460C/T and +405G/C polymorphisms and risk of endometriosis was observed. However, significant associations were observed between endometriosis risk and VEGF+936T polymorphism with summarized odds ratio of 1.19 (95%CI, 1.02-1.37), 1.18 (95%CI, 1.03-1.37), 1.15 (95%CI, 1.01-1.30) for CT versus CC genotype, dominant mode (CT/TT vs. CC) and allele comparison (T vs. C), respectively. Furthermore, stratified analysis showed that significantly strong association between +936T/C polymorphism and endometriosis was present only in stage III-IV (OR = 1.32 for dominant mode; OR = 1.30 for T vs. C), but not in stage I-II. However, no significantly increased risk of endometriosis was found in any of the genetic models in Asians or in Caucasians. This meta-analysis supports that VEGF+936T/C polymorphism is capable of causing endometriosis susceptibility.